Steering control methods, devices, vehicles and storage media

Abstract

This application provides a steering control method, device, vehicle, and storage medium. The steering control method is applied to a vehicle, whose steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel; the downward steering mechanism includes a rack mechanism and a downward steering drive motor. The steering control method includes: determining the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle; determining a basic feedback torque for the steering wheel based on the equivalent arm and the rack force corresponding to the rack mechanism; compensating the basic feedback torque based on the steering wheel torque applied by the user to obtain a target feedback torque; and driving the upward steering drive motor based on the target feedback torque. This solution improves the accuracy of steering feedback torque conversion and the simulation effect of the feel, thus enhancing the steering control experience.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of vehicle steering control technology, and in particular to a steering control method, device, vehicle, and storage medium. Background Technology

[0002] Currently, existing steering feel simulation solutions typically rely on high-precision torque sensors to collect the driver's hand force to construct steering feel feedback. To reduce hardware costs, steer-by-wire systems replace mechanical steering systems, eliminating the deceleration structure of the upper steering mechanism. Traditional feedback solutions that rely on sensors to directly detect torque are difficult to achieve accurate and realistic steering feel simulation. Summary of the Invention

[0003] In view of this, embodiments of this application provide a steering control method, device, vehicle, and storage medium.

[0004] The technical solution of this application embodiment is implemented as follows: In a first aspect, this application provides a steering control method applied to a vehicle. The vehicle's steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel. The downward steering mechanism includes a rack mechanism and a downward steering drive motor. The steering control method includes: determining the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle; the preset mapping relationship characterizes the correspondence between the steering wheel angle and the actual displacement of the rack mechanism; determining a basic feedback torque for the steering wheel based on the equivalent arm and the rack force corresponding to the rack mechanism; compensating the basic feedback torque based on the steering wheel torque applied by the user to obtain a target feedback torque; and driving the upward steering drive motor based on the target feedback torque.

[0005] In some embodiments, the current steering gear ratio is determined based on the vehicle's real-time speed and the current steering wheel angle; a preset mapping relationship is constructed based on the steering gear ratio, the current steering wheel angle, and the transmission efficiency; and the preset mapping relationship is differentiated relative to the current steering wheel angle to obtain the equivalent arm.

[0006] Based on the aforementioned technical methods, a variable steering gear ratio is dynamically matched with vehicle speed and steering wheel angle. A preset mapping relationship is constructed by combining the steering gear ratio, current steering wheel angle, and transmission efficiency. Then, differential calculations are used to solve for the instantaneous equivalent force arm. Compared to the traditional method of calculating the force arm using a fixed gear ratio and average ratio, this solution fully adapts to the working characteristics of variable gear ratios in steer-by-wire, enabling real-time capture of transmission patterns under different steering conditions. This results in more accurate conversion between rack force and steering wheel torque. No additional sensing equipment is required, simplifying the system hardware structure while ensuring real-time performance and stability. This provides a data foundation for subsequent calculations of target feedback torque and feel simulation.

[0007] In some embodiments, a desired displacement for the rack mechanism is determined based on the steering gear ratio and the current steering wheel angle; a downward drive torque of the downward drive motor is determined based on the desired displacement to drive the rack mechanism to move based on the downward drive motor.

[0008] Based on the aforementioned technical methods, the desired displacement of the rack mechanism is calculated by the steering gear ratio and steering wheel angle. Then, a downward driving torque is directly generated based on this desired displacement, thereby driving the rack mechanism to complete the steering action. Simultaneously, the displacement-torque curve, combined with the rack load, transmission friction, and other mechanical characteristics, completes the vehicle calibration, ensuring that the motor output torque matches the actual operating conditions, resulting in smooth and reliable rack movement. This guarantees a rapid response from the steering system, achieving synchronous linkage between steering wheel operation and vehicle steering.

[0009] In some embodiments, the inertial force of the rack mechanism is determined based on the vehicle's mass and the rack mechanism's displacement acceleration; the damping force of the rack mechanism is determined based on the rack mechanism's displacement velocity and the vehicle's damping coefficient; and the rack force is determined based on the rack mechanism's damping force, the rack mechanism's inertial force, and the downward driving torque.

[0010] Based on the aforementioned technical methods, the inertial force and damping force of the rack mechanism are calculated sequentially. Then, combined with the active thrust obtained from the downward driving torque, the total rack force is comprehensively solved. This fully recreates the actual force state of the rack mechanism during steering, making the calculated rack force more closely resemble actual working conditions. This provides data support for subsequent calculations of the feedback torque during steering, further enhancing the realism of the road feel simulation in the steer-by-wire system.

[0011] In some embodiments, a target compensation coefficient is determined based on steering wheel torque and vehicle operating data; a target feedback torque is determined based on the target compensation coefficient and the basic feedback torque.

[0012] Based on the aforementioned technical methods, the target compensation coefficient is dynamically calculated by combining steering wheel torque and vehicle operating data. This target compensation coefficient is then used to compensate for the base feedback torque, resulting in the final target feedback torque. This method can flexibly adjust the steering feedback torque based on the driver's input force and the vehicle's real-time operating conditions, adapting to the feel requirements of different driving scenarios. Simultaneously, torque limiting and smoothing processes prevent drastic fluctuations in feedback torque, ensuring a consistent and comfortable steering feel. Thus, the target feedback torque accurately reproduces the real road feel while improving steering safety and the overall driving experience.

[0013] In some embodiments, the operating data includes vehicle yaw rate, angular acceleration of the up-rotation drive motor, and rotational speed of the up-rotation drive motor; an external force compensation coefficient is determined based on steering wheel torque; a motion compensation coefficient is determined based on yaw rate; a motor compensation coefficient is determined based on the angular acceleration and rotational speed of the up-rotation drive motor; and a target compensation coefficient is determined based on the external force compensation coefficient, motion compensation coefficient, and motor compensation coefficient.

[0014] Based on the aforementioned technical methods, the external force compensation coefficient, motion compensation coefficient, and motor compensation coefficient are calculated sequentially based on the steering wheel torque, vehicle yaw rate, upward angular velocity, and upward rotation speed. These three types of compensation coefficients are then fused to obtain a comprehensive target compensation coefficient. In this way, deviation compensation is achieved from multiple dimensions, including road surface interference, vehicle dynamic attitude, and the characteristics of the drive motor itself, comprehensively correcting steering torque errors. This allows the steering feedback torque to accurately match various operating conditions, effectively optimizing steering feel and improving the precision and stability of the vehicle's steering control.

[0015] In some embodiments, the inertial torque of the steering wheel is determined based on the steering wheel angular acceleration and the steering wheel moment of inertia; the damping torque of the steering wheel is determined based on the steering wheel angular velocity and the damping coefficient; and the steering wheel torque is determined based on the inertial torque of the steering wheel, the damping torque of the steering wheel, the upward drive torque of the upward drive motor, and the frictional torque of the steering wheel.

[0016] Based on the aforementioned technical methods, the steering wheel torque is obtained by comprehensively considering the steering wheel's inertial torque, damping torque, frictional torque, and the driving torque of the upper drive motor. This allows for the accurate reproduction of the actual force on the steering wheel during rotation, thus estimating the real-time steering wheel torque applied by the user. This enables dynamic adaptation to different steering operations and driving conditions, effectively improving the feel, smoothness, and control precision of the steer-by-wire system.

[0017] Secondly, embodiments of this application provide a steering control device applied to a vehicle. The vehicle's steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel. The downward steering mechanism includes a rack mechanism and a downward steering drive motor. The steering control device includes: a first determining module, used to determine the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle; the preset mapping relationship characterizes the correspondence between the steering wheel angle and the actual displacement of the rack mechanism; a second determining module, used to determine the basic feedback torque for the steering wheel based on the equivalent arm and the rack force corresponding to the rack mechanism; a compensation module, used to compensate the basic feedback torque based on the steering wheel torque applied by the user to obtain a target feedback torque; and a driving module, used to drive the upward steering drive motor based on the target feedback torque.

[0018] Thirdly, embodiments of this application provide a vehicle, which includes a memory, a vehicle controller, and a steering system. The memory stores a computer program that can run on the vehicle controller. When the vehicle controller executes the program, it implements some or all of the steps in the above-described method. The steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward steering drive motor rigidly connected to a steering wheel. The downward steering mechanism includes a rack mechanism and a downward steering drive motor.

[0019] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a vehicle controller, implements some or all of the steps in the above-described method.

[0020] The beneficial effects of this application are as follows: The instantaneous equivalent force arm is calculated by combining a preset mapping relationship, the current steering wheel angle, and the actual displacement of the rack; the basic feedback torque is obtained based on the rack force received by the rack mechanism and the equivalent force arm; multi-dimensional torque compensation is then completed using the driver's steering wheel torque, vehicle and motor operating data, ultimately driving the upward-turning drive motor to simulate the steering feel. This solution relies on software algorithms to calculate rack force and human hand torque, and dynamically compensate for torque, eliminating the need for additional torque sensors and rack force sensors, thus simplifying the hardware structure of the steer-by-wire system. Compared to existing steer-by-wire solutions that rely on various sensing elements to collect signals and use a fixed force arm for torque conversion, this solution calculates the instantaneous equivalent force arm, adapting to variable steering ratio working scenarios. This reduces hardware costs while improving the accuracy of steering feedback torque conversion and the steering feel simulation effect, thereby enhancing the steering control experience.

[0021] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of this application. Attached Figure Description

[0022] In the accompanying drawings (which are not necessarily drawn to scale), similar reference numerals may describe similar parts in different views. Similar reference numerals with different letter suffixes may indicate different examples of similar parts. The drawings illustrate, by way of example and not limitation, the various embodiments discussed herein.

[0023] Figure 1 A schematic diagram illustrating the implementation process of a steering control method provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the implementation framework of a steering control method provided in this application embodiment; Figure 3 This is a schematic diagram of the composition structure of a steering control device provided in an embodiment of this application; Figure 4 This is a schematic diagram of the hardware entity of a vehicle provided in an embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of this application will be provided in conjunction with the accompanying drawings. The described embodiments should not be considered as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0025] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the specific embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the disclosure of the present application to those skilled in the art.

[0026] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, to avoid confusion with this application, some technical features well-known in the art have not been described; that is, not all features of actual embodiments are described herein, nor are well-known functions and structures described in detail.

[0027] In the accompanying drawings, for clarity, the dimensions of layers, areas, and elements, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “ / the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The technical and scientific terms used herein are for the purpose of describing embodiments of this application only and do not limit the scope of this application.

[0030] Currently, with the continuous advancement of intelligent driving and vehicle electrification, steer-by-wire systems are gradually replacing traditional mechanical steering systems. Steer-by-wire systems eliminate the mechanical transmission structure between the steering wheel and wheels, relying instead on electronic components and actuators to achieve steering control. They use high-precision torque sensors to collect the driver's hand torque, thus constructing the steering feel feedback logic. To reduce hardware costs, steer-by-wire systems eliminate the reduction gear structure and torque sensor of the upper steering mechanism. Traditional feedback schemes that rely on sensors to directly detect torque are no longer viable, making it difficult to achieve accurate and realistic steering feel output.

[0031] To address the aforementioned technical issues, this application provides a steering control method that calculates the instantaneous equivalent arm by combining a preset mapping relationship, the current steering wheel angle, and the actual displacement of the rack; obtains the basic feedback torque based on the rack force received by the rack mechanism and the equivalent arm; and then completes multi-dimensional torque compensation using the driver's steering wheel torque, vehicle and motor operating data. This solution relies on software algorithms to calculate rack force and human hand torque and dynamically compensate for torque, eliminating the need for additional torque sensors and rack force sensors, thus simplifying the hardware structure of the steer-by-wire system. Compared to existing steer-by-wire solutions that rely on various sensing elements to collect signals and use a fixed arm for torque conversion, this solution calculates the instantaneous equivalent arm, adapting to variable steering ratio operating scenarios. This reduces hardware costs while improving the accuracy of steering feedback torque conversion and the feel simulation effect, thereby enhancing the steering control experience.

[0032] Figure 1 This is a schematic diagram illustrating the implementation flow of a steering control method provided in an embodiment of this application. The method is applied to a vehicle and can be executed by the vehicle's controller. The vehicle's steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward drive motor rigidly connected to the steering wheel; the downward steering mechanism includes a rack mechanism and a downward drive motor. Figure 1 As shown, the method includes the following steps S101 to S104, combining... Figure 1 The steps shown are explained.

[0033] Step S101: Based on the preset mapping relationship and the current steering wheel angle, determine the equivalent force arm between the steering wheel and the rack mechanism.

[0034] The preset mapping relationship represents the correspondence between the steering wheel angle and the actual displacement of the rack mechanism.

[0035] In some embodiments, the upward rotation mechanism further includes an upward rotation controller and a steering wheel angle sensor; the downward rotation mechanism further includes a downward rotation controller; the upward rotation controller and the downward rotation controller are connected in communication; the steering wheel angle sensor collects the steering wheel angle in real time and sends it to the upward rotation controller; the controller determines the equivalent arm between the steering wheel and the rack mechanism according to the steering wheel angle and a preset mapping relationship.

[0036] In some embodiments, the equivalent force arm characterizes the instantaneous transmission relationship between the steering wheel angle and the rack displacement; when the steering wheel undergoes angular displacement, the change in linear displacement of the rack in the rack mechanism reflects the equivalent ratio of the linear force received by the rack to the steering wheel rotation torque.

[0037] In some embodiments, the preset mapping relationship is pre-calibrated based on the characteristics of the vehicle steering transmission structure, the transmission ratio, and the transmission efficiency, and can reflect the actual displacement change law of the rack mechanism under different steering wheel angles.

[0038] In some embodiments, the real-time steering angle of the steering wheel is first obtained by the steering wheel angle sensor and the real-time vehicle speed is obtained. The vehicle speed and steering wheel angle are then combined with a pre-stored data table to determine the variable steering ratio under the current operating conditions of the vehicle.

[0039] In some embodiments, after obtaining the current steering gear ratio, the actual displacement corresponding to the rack mechanism is calculated by combining the steering wheel angle, system transmission efficiency, and a preset mapping relationship. Differential calculation is then performed using the actual displacement of the rack mechanism as the dependent variable and the steering wheel angle as the independent variable to obtain the instantaneous equivalent force arm. The equivalent force arm is used to equivalently convert the force at the rack end into the feedback torque at the steering wheel end.

[0040] Step S102: Determine the basic feedback torque for the steering wheel based on the rack force corresponding to the equivalent force arm and rack mechanism.

[0041] In some embodiments, the rack force is the external load force exerted by the road surface and tires on the rack mechanism, which can accurately reflect the resistance transmitted from the road surface to the steering system during vehicle operation.

[0042] In some embodiments, the rack force is calculated by the down-rotation controller based on the rack dynamics model, combining the motion state parameters of the rack mechanism and the operating parameters of the down-rotation drive motor.

[0043] In some embodiments, the product of the calculated rack force equivalent force arms is used as the basic feedback torque corresponding to the steering wheel, as shown in the following formula (1); the basic feedback torque directly corresponds to the steering feedback feel brought about by the road resistance.

[0044] Formula (1) in, Basic feedback torque; The rack force received by the rack mechanism; It is an equivalent arm.

[0045] Step S103: Compensate the basic feedback torque based on the steering wheel torque applied by the user to obtain the target feedback torque.

[0046] In some embodiments, the steering wheel torque applied by the user refers to the hand torque when the user turns the steering wheel; wherein, the steering wheel torque is calculated by the controller based on the operating data of the drive motor and the frictional force when the steering wheel moves.

[0047] In some embodiments, the steering wheel torque applied by the user can reflect the force and intention of the user when turning the steering wheel. The magnitude and rate of change of this torque will directly change the force state of the steering system, thereby affecting the steering feedback feel.

[0048] Specifically, when a user lightly turns the steering wheel, the input torque is relatively small. If the basic feedback torque is directly output, the steering resistance will be too high and the steering feel will be heavy. When a user quickly and forcefully turns the steering wheel, the input torque is large, and the basic feedback torque will feel insufficient and the steering feel will be vague, failing to match the driver's operating rhythm. Therefore, it is necessary to compensate for the basic feedback torque through steering wheel torque.

[0049] In some embodiments, the corresponding external force compensation coefficient is queried from the preset torque compensation curve based on the steering wheel torque, and the basic feedback torque is compensated based on the external force compensation coefficient to obtain the target feedback torque.

[0050] In some embodiments, the basic feedback torque can also be compensated using the vehicle's motion data and the motion data of the up-rotation drive motor to obtain a motion compensation coefficient, thereby compensating for the basic feedback torque.

[0051] Step S104: Drive the upward drive motor based on the target feedback torque.

[0052] In some embodiments, the up-turn controller converts the obtained target feedback torque into a control command for the up-turn drive motor, outputs a corresponding control signal through the motor drive circuit, controls the up-turn drive motor to output a matching torque, and thereby drives the steering wheel to generate corresponding steering feedback resistance.

[0053] In some embodiments, the controller further determines the return torque and end protection torque of the steering wheel based on the physical characteristics of the steering wheel; and superimposes the return torque and end protection torque of the steering wheel on the target feedback torque to drive the up-rotation drive motor according to the superimposed target feedback torque.

[0054] In some embodiments, the up-drive motor is rigidly connected to the steering wheel, and the motor output torque can be directly applied to the steering wheel without intermediate transmission backlash. This allows the driver to perceive the steering feedback torque in real time without delay, ensuring the synchronization of operation and feel.

[0055] In some embodiments, the up-rotation controller performs closed-loop monitoring of the torque commands sent to the motor, collecting real-time operating parameters such as the actual output torque, speed, and angle of the up-rotation drive motor, and transmitting the collected results back to the up-rotation controller. The up-rotation controller compares the actual output torque of the motor with the target feedback torque. If there is a deviation between the two, it dynamically corrects the motor control commands to achieve closed-loop torque adjustment, ensuring that the motor output torque accurately follows the target feedback torque.

[0056] In some embodiments, when the rack mechanism is detected to have reached the mechanical limits on the left and right sides, the maximum output torque of the drive motor can be limited to a preset threshold by the limiting effect of the end protection torque. This not only simulates the limit feel of turning the steering wheel all the way, but also prevents the motor from stalling or overloading for a long time, effectively protecting the motor body and mechanical structures such as gears, racks, and steering tie rods.

[0057] In some embodiments, after the vehicle is in normal driving mode and the steering operation is completed, the upper drive motor, in conjunction with the output logic of the return torque, completes the automatic return of the steering wheel, avoiding the phenomenon of the steering wheel returning too quickly, shaking or jamming, and further improving driving comfort.

[0058] In this embodiment, the instantaneous equivalent arm is calculated by combining a preset mapping relationship, steering wheel angle, and actual rack displacement; the basic feedback torque is obtained based on the rack force received by the rack mechanism and the equivalent arm; multi-dimensional torque compensation is then completed using the driver's steering wheel torque, vehicle and motor operating data, and finally, the return torque and end-of-line protection torque are combined to drive the upward drive motor. This solution relies on software algorithms to calculate rack force and human hand torque and dynamically compensate for torque, eliminating the need for additional torque sensors and rack force sensors, thus simplifying the hardware structure of the steer-by-wire system. Compared to existing steer-by-wire solutions that rely on various sensing elements to collect signals and use a fixed arm for torque conversion, this solution calculates the instantaneous equivalent arm to adapt to variable steering ratio operating scenarios, reducing hardware costs while improving the accuracy of steering feedback torque conversion and the feel simulation effect, thereby enhancing the steering control experience.

[0059] In some embodiments, step S101 may include the following implementation process.

[0060] Step S21: Determine the current steering gear ratio based on the vehicle's real-time speed and the current steering wheel angle.

[0061] In some embodiments, the real-time speed of a vehicle can be obtained in real time through on-board vehicle speed sensors, wheel speed sensors, etc.

[0062] In some embodiments, the steering ratio is the ratio between the steering wheel rotation and the linear displacement generated by the rack mechanism, characterizing the transmission relationship of steering motion.

[0063] In some embodiments, the linear steering system of this application employs a variable steering gear ratio; wherein, when the vehicle is traveling at low speed and the steering wheel angle is large, a smaller gear ratio is selected, resulting in a larger rack displacement for the same steering wheel angle, thereby improving steering flexibility; when the vehicle is traveling at high speed and the steering wheel angle is small, a larger gear ratio is selected, resulting in a smaller rack displacement for the same steering wheel angle, thereby enhancing driving stability.

[0064] In some embodiments, the steering ratio for the current operating condition is determined from a pre-calibrated gear ratio curve based on the real-time speed and steering wheel angle.

[0065] Step S22: Construct a preset mapping relationship based on the steering gear ratio, the current steering wheel angle, and the transmission efficiency.

[0066] In some embodiments, transmission efficiency is a fixed parameter pre-calibrated for the steering transmission mechanism, used to characterize the energy loss of steering motion and force during transmission.

[0067] In some embodiments, a preset mapping relationship between the actual displacement of the rack mechanism and the steering wheel angle can be constructed based on the steering ratio, steering wheel angle and transmission efficiency, as shown in the following formula (2).

[0068] Formula (2) in, This represents the actual displacement of the rack and pinion mechanism; Steering wheel angle; This refers to the steering gear ratio; For transmission efficiency; This refers to a preset mapping relationship; where the preset mapping relationship can be... .

[0069] Step S23: Perform a differential operation on the preset mapping relationship relative to the current steering wheel angle to obtain the equivalent arm.

[0070] In some embodiments, the independent variable of the differential operation is the steering wheel angle, and the dependent variable is a preset mapping relationship. The result of the operation is the instantaneous equivalent force arm under the current operating condition. This parameter represents the equivalent conversion ratio between the linear force and the turning torque in the steering system. Specifically, the up-steering controller constructs a preset mapping relationship with the steering wheel angle according to a fixed sampling period, and performs discrete differential calculations based on sampling data from adjacent time points, thereby approximating continuous differential operations and adapting to the real-time computing capabilities of the vehicle controller.

[0071] In some embodiments, the following formula (3) can be used to perform differential calculation on the preset mapping relationship relative to the steering wheel angle to obtain the equivalent arm.

[0072] Formula (3) In some embodiments, differential operations are used to characterize the instantaneous change of the rack's actual displacement with the steering wheel angle, which can accurately reflect the instantaneous transmission characteristics at any steering position.

[0073] In this embodiment, a preset mapping shift is constructed by dynamically matching the vehicle speed and steering wheel angle with the variable steering gear ratio, and then the instantaneous equivalent force arm is solved using differential operations. Compared with the traditional method of calculating the force arm using a fixed gear ratio and average ratio, this solution fully adapts to the working characteristics of the variable gear ratio in steer-by-wire, and can capture the transmission law under different steering conditions in real time, making the conversion result of rack force and steering wheel torque more accurate. No additional sensing equipment is required, which simplifies the system hardware structure while ensuring real-time performance and stability, providing a data foundation for the accurate calculation of the target feedback torque and the simulation of the feel.

[0074] In some embodiments, the steering control method described above further includes the following implementation process.

[0075] Step S31: Determine the desired displacement for the rack mechanism based on the steering gear ratio and the current steering wheel angle.

[0076] In some embodiments, the desired displacement is the target straight-line position that the rack mechanism theoretically needs to reach.

[0077] In some embodiments, the up-turn controller retrieves the current real-time steering transmission ratio and the collected steering wheel angle to solve for the desired displacement of the rack mechanism, which can be referred to in the following formula (4).

[0078] Formula (4) in, The desired displacement.

[0079] In some embodiments, after the up-turn controller calculates the desired displacement, it sends the desired displacement to the down-turn controller.

[0080] Step S32: Determine the downward driving torque of the downward drive motor based on the desired displacement, so as to drive the rack mechanism to move based on the downward drive motor.

[0081] In some embodiments, after receiving the desired displacement sent by the upshift controller, the downshift controller retrieves the pre-calibrated displacement-torque curve and generates the downshift driving torque based on the desired displacement.

[0082] In some embodiments, the down-turn controller converts the generated down-turn drive torque into a control command for the down-turn drive motor, and outputs a corresponding control signal through the down-turn drive motor drive circuit. This controls the down-turn drive motor to output a torque that matches the down-turn drive torque, directly driving the rack mechanism to produce linear displacement. The movement of the rack mechanism further drives the steering actuator to move, ultimately achieving vehicle steering.

[0083] In some embodiments, the pre-calibrated displacement-torque curve is based on the mechanical characteristics of the rack mechanism itself, such as load and transmission friction resistance, to ensure that the motor output torque can stably drive the rack under different desired displacements.

[0084] In this embodiment, the desired displacement of the rack mechanism is calculated using the steering gear ratio and steering wheel angle. Then, a downward driving torque is directly generated based on this desired displacement, thereby driving the rack mechanism to complete the steering action. Simultaneously, the displacement-torque curve, combined with mechanical characteristics such as rack load and transmission friction, completes vehicle calibration, ensuring that the motor output torque matches the actual operating conditions and that the rack movement is smooth and reliable. This control method has simple logic and low computational load, ensuring a rapid response from the steering system and achieving synchronous linkage between steering wheel operation and vehicle steering.

[0085] In some embodiments, the steering control method described above further includes the following implementation process.

[0086] Step S41: Determine the inertial force of the rack mechanism based on the vehicle's mass and the rack mechanism's displacement acceleration.

[0087] In some embodiments, the displacement acceleration of the rack mechanism is the instantaneous acceleration of the rack when it moves in a straight line. It can be obtained by performing a second-order time-domain differential operation on the real-time displacement signal of the rack, reflecting the rate of change of the rack's motion state.

[0088] In some embodiments, the inertial force of the rack mechanism can be calculated using the following formula (5).

[0089] Formula (5) in, The inertial force of the rack and pinion mechanism; Vehicle quality; This represents displacement acceleration.

[0090] Step S42: Determine the damping force of the rack mechanism based on the displacement velocity of the rack mechanism and the damping coefficient of the vehicle.

[0091] In some embodiments, the displacement velocity of the rack mechanism is the instantaneous velocity of the rack's linear motion, which can be obtained by performing a first-order time-domain differential operation on the real-time displacement signal of the rack, characterizing the speed of the rack's motion.

[0092] In some embodiments, the damping coefficient is a fixed parameter pre-calibrated for the steering system, reflecting the damping characteristics between the steering transmission structure and motion.

[0093] In some embodiments, the damping force of the rack mechanism can be calculated using the following formula (6).

[0094] Formula (6) in, The damping force of the rack and pinion mechanism; The damping coefficient; The displacement speed of the rack and pinion mechanism.

[0095] Step S43: Determine the rack force based on the damping force of the rack mechanism, the inertial force of the rack mechanism, and the downward driving torque.

[0096] In some embodiments, the downward drive torque output by the downward drive motor is converted into an active drive force acting on the rack through the steering transmission structure; combined with the mechanism transmission relationship, the downward drive torque can be converted into an active thrust at the rack end.

[0097] In some embodiments, the rack force is the combined resultant force acting on the rack mechanism, obtained by superimposing the active thrust, inertial force, and damping force. The inertial force and damping force are both load forces that impede the movement of the rack.

[0098] In some embodiments, the rack force can be calculated with reference to the following formula (7).

[0099] Formula (7) In some embodiments, this application integrates the active force and various motion resistances during the steering motion process to fully restore the actual force situation of the rack, so that the rack force obtained can truly reflect the load feedback brought by the road surface and mechanical structure.

[0100] In this embodiment, the inertial force and damping force of the rack mechanism are calculated sequentially, and then combined with the active thrust obtained by converting the downward driving torque to comprehensively solve for the total rack force. This fully restores the actual force state of the rack mechanism during steering motion, making the calculated rack force more consistent with actual working conditions. This provides data support for subsequent calculations of the feedback torque during steering, further improving the realism of the road feel simulation of the steer-by-wire system.

[0101] In some embodiments, step S103 may include the following implementation process.

[0102] Step S51: Determine the target compensation coefficient based on the steering wheel torque and vehicle operating data.

[0103] In some embodiments, the steering wheel torque is the hand torque calculated by the controller using the operating parameters of the up-rotation drive motor and the steering friction parameters, reflecting the driver's steering effort and operating intention.

[0104] In some embodiments, vehicle operating data includes parameters such as vehicle speed, yaw rate, and up-rotation drive motor speed, which are used to characterize the real-time motion conditions of the vehicle and the operating status of the steering mechanism.

[0105] In some embodiments, the up-turn controller has multiple sets of calibration curves and data tables pre-stored, corresponding to the relationships between steering wheel torque, various vehicle operating data, and compensation coefficients. The controller uses steering wheel torque and vehicle operating data as query conditions to initially obtain the sub-item compensation coefficients through table lookup, linear interpolation, and other methods.

[0106] In some embodiments, the obtained individual compensation coefficients are fused to obtain the final target compensation coefficient. The fusion method may employ preset operation logic such as weighted multiplication or weighted summation.

[0107] In some embodiments, it is used to adjust the amplitude of the basic feedback torque. Step S52: Determine the target feedback torque based on the target compensation coefficient and the basic feedback torque.

[0108] In some embodiments, the target compensation coefficient is used to dynamically adjust the amplitude of the basic feedback torque, optimizing the steering feedback feel in conjunction with the driver's operating force and the overall vehicle operating conditions. The target compensation coefficient changes dynamically with the steering wheel torque and the vehicle's operating state. When the driver lightly turns the steering wheel and the vehicle is traveling at low speed, the target compensation coefficient decreases accordingly, weakening the feedback resistance; when the driver turns the steering wheel forcefully and the vehicle is traveling at high speed, the target compensation coefficient increases accordingly, strengthening the steering damping feel.

[0109] In some embodiments, the target compensation coefficient is multiplied by the basic feedback torque to obtain the corrected target feedback torque.

[0110] In some embodiments, the calculated target feedback torque is also limited by upper and lower limits to avoid excessive torque causing heavy steering or insufficient torque affecting driving safety.

[0111] In this embodiment, the target compensation coefficient is dynamically calculated by combining steering wheel torque and vehicle operating data. The target compensation coefficient is then used to correct the amplitude of the base feedback torque, resulting in the final target feedback torque. This method can flexibly adjust the steering feedback torque based on the driver's operating force and the vehicle's real-time operating conditions, adapting to the feel requirements of different driving scenarios. Simultaneously, torque limiting and smoothing processes prevent drastic fluctuations in feedback torque, ensuring a consistent and comfortable steering feel. Thus, the target feedback torque accurately reproduces the real road feel while improving steering safety and the driving experience.

[0112] In some embodiments, the operating data includes the vehicle yaw rate, the upward rotational angular velocity of the upward drive motor, and the upward rotational speed; the above step S1031 includes the following process.

[0113] Step S61: Determine the external force compensation coefficient based on the steering wheel torque.

[0114] In some embodiments, the external force compensation coefficient is mainly used to compensate for torque deviations caused by external additional resistance and lateral forces on the road surface during steering, so that the steering feedback is more in line with the actual driving conditions.

[0115] In some embodiments, the steering controller has pre-stored the corresponding calibration curves and data tables of steering wheel torque and external force compensation coefficient. Based on the real-time collected steering wheel torque, the corresponding external force compensation coefficient can be obtained by looking up the table and performing interpolation calculations.

[0116] In some embodiments, when the steering wheel torque is too large, the external force compensation coefficient is increased accordingly to offset the effect of the additional load; when the steering wheel torque is too small, the compensation coefficient is decreased accordingly to maintain a balanced steering feel.

[0117] Step S62: Determine the motion compensation coefficient based on the yaw rate.

[0118] In some embodiments, the yaw rate reflects the speed at which the vehicle rotates around its vertical axis, embodying the dynamic motion state of the vehicle during steering, and can be collected in real time by an onboard attitude sensor.

[0119] In some embodiments, the motion compensation coefficient is used to compensate for torque deviations caused by changes in vehicle body posture during steering. The greater the yaw rate, the more drastic the change in vehicle steering posture, and the greater the motion compensation coefficient, thus enhancing steering feedback; as the yaw rate approaches zero, the compensation coefficient decreases accordingly.

[0120] In some embodiments, the controller has a pre-set calibration comparison table and characteristic curve of yaw speed and motion compensation coefficient. The corresponding motion compensation coefficient is obtained by combining the real-time yaw speed as the query basis and interpolation calculation.

[0121] Step S63: Determine the motor compensation coefficient based on the angular acceleration and rotational speed of the upper drive motor.

[0122] In some embodiments, the motor compensation coefficient is used to compensate for torque errors caused by the inherent characteristics of the motor, such as operating friction, speed fluctuation, and dynamic response lag, thereby improving the output accuracy of the motor.

[0123] In some embodiments, when the motor speed and steering wheel rotation speed are relatively high, the motor compensation coefficient is appropriately increased to offset the additional resistance generated by high-speed operation; the compensation coefficient is decreased when the speed is low or when stationary.

[0124] In some embodiments, the up-rotation controller has a pre-calibrated correspondence table and characteristic curves built in, and obtains the motor compensation coefficient by looking up the table and interpolating the real-time up-rotation angular velocity and up-rotation speed.

[0125] In some embodiments, the inertial compensation term can be determined by the angular acceleration of the upward drive motor; the damping compensation term can be determined based on the rotational speed of the upward drive motor; the friction compensation term can be determined based on the friction model of the upward drive motor; and the inertial compensation term, damping compensation term, and friction compensation term can be fused to obtain the motor compensation coefficient.

[0126] Step S64: Determine the target compensation coefficient based on the external force compensation coefficient, motion compensation coefficient, and motor compensation coefficient.

[0127] In some embodiments, the three types of compensation coefficients are fused and calculated according to preset calculation rules to obtain the target compensation coefficient of the comprehensive effect. The commonly used calculation method is multiplication or weighted summation.

[0128] In some embodiments, the target compensation coefficient can be calculated with reference to the following formula (8).

[0129] Formula (8) in, The target compensation coefficient; is the external force compensation coefficient, and 'a' is the weight of the external force compensation coefficient; is the motion compensation coefficient, and b is the weight of the motion compensation coefficient; denoted as , where c is the motor compensation coefficient and is the weight of the motor compensation coefficient.

[0130] In this embodiment, the external force compensation coefficient, motion compensation coefficient, and motor compensation coefficient are calculated sequentially based on the steering wheel torque, vehicle yaw rate, upward angular velocity, and upward rotation speed. These three types of compensation coefficients are then fused to obtain a comprehensive target compensation coefficient. This approach compensates for deviations from multiple dimensions, including road surface interference, vehicle dynamic posture, and the characteristics of the drive motor itself, comprehensively correcting steering torque errors. This allows the steering feedback torque to accurately match various operating conditions, effectively optimizing steering feel and improving the precision and stability of the vehicle's steering control.

[0131] In some embodiments, the steering wheel torque can be determined in the following manner.

[0132] Step S71: Determine the inertial torque of the steering wheel based on the steering wheel angular acceleration and the steering wheel moment of inertia.

[0133] In some embodiments, the steering wheel angular acceleration characterizes the rate of change of the steering wheel rotation speed, and can be obtained by performing a second-order differential operation on the steering wheel angle signal.

[0134] In some embodiments, the moment of inertia of the steering wheel is an inherent parameter of the steering wheel and its connected rotating components, obtained through vehicle calibration, and is a fixed constant.

[0135] In some embodiments, the moment of inertia can be calculated with reference to the following formula (9).

[0136] Formula (9) in, The inertial torque of the steering wheel; The moment of inertia of the steering wheel; This refers to the angular acceleration of the steering wheel.

[0137] Step S72: Determine the damping torque of the steering wheel based on the angular velocity and damping coefficient of the steering wheel.

[0138] In some embodiments, the steering wheel angular velocity reflects the real-time rotation speed of the steering wheel and can be obtained by performing a first-order differential operation on the steering angle signal.

[0139] In some embodiments, the damping coefficient is a preset calibration value of the steering mechanism, which comprehensively reflects the damping characteristics of the rotating and transmission components.

[0140] In some embodiments, the damping torque is positively correlated with the angular velocity; the faster the steering wheel is turned, the greater the damping torque; when stationary, the damping torque is approximately zero. The damping torque can be calculated using the following formula (10).

[0141] Formula (10) in, The damping torque of the steering wheel; The angular velocity of the steering wheel.

[0142] Step S73: Determine the steering wheel torque based on the inertial torque of the steering wheel, the damping torque of the steering wheel, the upward drive torque of the upward drive motor, and the frictional torque of the steering wheel.

[0143] In some embodiments, the upward drive torque is the torque actually output by the upward drive motor, which is the target feedback torque determined by the upward controller at the previous moment.

[0144] In some embodiments, the frictional torque is the constant resistance torque generated by mechanical friction when the steering wheel is rotated, which is obtained by actual measurement and calibration of the whole vehicle.

[0145] In some embodiments, the steering wheel torque can be calculated using the following formula (11).

[0146] Formula (11) in, Steering wheel torque, This refers to the upward driving torque of the upward drive motor. This refers to the frictional torque of the steering wheel.

[0147] In this embodiment, the steering wheel torque is obtained by combining the steering wheel inertial torque, damping torque, friction torque, and the driving torque of the upper drive motor. This comprehensively considers various mechanical loads during steering wheel rotation, accurately reproducing the actual force on the steering wheel, and thus estimating the real-time steering wheel torque applied by the user. This allows for dynamic adaptation to different steering operations and driving conditions, effectively improving the feel, smoothness, and control precision of the steer-by-wire system.

[0148] The following describes an exemplary application of a steering control method provided in this application in a real-world scenario.

[0149] The steering control method provided in this application relates to the field of automotive steer-by-wire technology, and in particular to a control algorithm for a direct-drive up-steering system without a torque sensor, which estimates the force of the down-turning rack and realizes steering wheel road feel feedback.

[0150] With the development of intelligent driving and electrification technologies, traditional mechanical steering systems are gradually being replaced by steer-by-wire (SbW) systems. The SbW system eliminates the mechanical drive shaft between the steering wheel and the wheels, replacing it with sensors, controllers, and actuator motors, thereby achieving greater freedom of movement and safety.

[0151] Current steer-by-wire systems mostly use high-precision torque sensors to detect the driver's hand force as one of the basic signals for feel feedback. However, in steer-by-wire systems, in order to reduce costs, the deceleration mechanism and torque sensor of the steer-by-wire mechanism have been eliminated. Therefore, a feel feedback control method that does not rely on torque sensors is needed.

[0152] In response, this application provides a steer-by-wire feedback control method that does not require a torque sensor at the steering wheel end. It utilizes the rack force information calculated by the lower steering system, combined with the steering transmission ratio, vehicle speed information, motor speed information, and dynamic compensation algorithm, to accurately estimate the feedback torque that the driver should perceive, and outputs it in real time by the direct-drive upper steering motor, thereby achieving natural, adjustable, and safe steering wheel feedback.

[0153] This application provides a method for providing tactile feedback control of a direct-drive up-turn steering system. The system comprises: a steering wheel assembly (corresponding to the up-turn mechanism in the above embodiment), a down-turn actuator (corresponding to the down-turn mechanism in the above embodiment), and a vehicle status information interface. The steering wheel assembly includes a direct-drive torque motor, an up-turn controller, and a steering wheel angle sensor. The direct-drive motor is rigidly connected to the steering wheel, achieving torque feedback with zero mechanical transmission chain and providing rapid response. It is used to output feedback torque. The steering wheel angle controller is used to collect the steering wheel angle. The down-turn actuator includes a down-turn controller, a pinion-rack mechanism, and its drive motor, used to achieve front wheel steering and calculate rack force based on the down-turn rack displacement and motor torque. The vehicle status information interface and plane are used to acquire vehicle speed, yaw rate, lateral acceleration, etc.

[0154] Figure 2 The implementation framework diagram of a steering control method provided in this application includes a basic torque calculation module 201, a return torque calculation module 202, an end protection torque calculation module 203, and a motor control module 204.

[0155] In some embodiments, the basic torque calculation module 201 calculates the basic feedback torque based on the steering wheel angle, the rack force of the rack mechanism, and vehicle signals (vehicle speed, yaw rate, lateral acceleration), and compensates the basic feedback torque to obtain the target feedback torque.

[0156] First, establish the steering wheel angle. And rack displacement of rack mechanism The mapping relationship; referring to the above formula (2), the down-turn controller determines the actual rack displacement based on the steering wheel angle, variable transmission ratio, transmission efficiency, and mapping relationship; referring to the above formula (3), the equivalent force arm is determined based on the actual rack displacement and steering wheel angle; referring to the above formula (1), the basic feedback torque is determined based on the equivalent force arm and rack force.

[0157] In some embodiments, the downshift controller determines the system mass (e.g., vehicle mass), damping coefficient, rack displacement acceleration, and rack displacement velocity based on these parameters. The rack force is determined by the torque of the lower motor, which can be referred to in the above formula (7).

[0158] Among them, the kinematic equations of the drive motor and the driver's hand force (corresponding to the steering wheel torque in the above embodiment) are established, and the driver's hand force is estimated. The above formula (11) can be used as a reference to determine the external force compensation coefficient based on the hand force, and the basic feedback torque is compensated according to the external force compensation coefficient.

[0159] Specifically, the basic feedback torque gain coefficient (corresponding to the motion compensation coefficient in the above embodiment) is calculated based on the vehicle yaw rate, and the basic torque is compensated based on the torque gain coefficient, so that the vehicle can obtain richer feedback performance in some scenarios.

[0160] In some embodiments, in order to make the tactile feedback response more timely and smooth, the basic feedback torque is compensated accordingly, and the compensator is designed as follows (12).

[0161] (s)=K Formula (12) in, (s) represents phase compensation, K is the gain, Z1 and Z2 are zeros, and P1 and P2 are poles. By adjusting the positions of the poles and zeros, the compensated open-loop system has an appropriate phase lead in a specific frequency band, which improves the response speed and suppresses high-frequency noise.

[0162] In some embodiments, a safety limit is set for the output basic feedback torque. The safety limit is obtained by looking up a table based on the rack force and vehicle speed to ensure that the output torque does not exceed the safety threshold.

[0163] In some embodiments, a Notch filter is used to adjust the phase characteristics of the basic feedback torque to obtain a stable driving feel, and its transfer function is as follows (13).

[0164] Formula (13) in, For notch filter gain, , Set the damping at the zero point. Set the damping at the pole so that... A notch is generated at the natural frequency to suppress noise. The resonance generated at that location.

[0165] In some embodiments, in order to obtain a more realistic feel, inertia, damping and friction compensation terms are added, wherein the inertia is based on the angular acceleration of the upper rotating motor, the damping is based on the rotational speed of the upper rotating motor, and the friction compensation term is calculated based on the friction model of the upper rotating system.

[0166] In some embodiments, the motor control module 204 superimposes the target feedback torque output by the basic torque calculation module 201, the steering wheel return torque output by the return torque calculation module 202, and the end protection torque output by the end protection torque calculation module 203 to obtain the final feel feedback torque, and drives the up-rotation drive motor according to the feel feedback torque.

[0167] Figure 3 This is a schematic diagram of the composition of a steering control device provided in an embodiment of this application, as shown below. Figure 3 As shown, the steering control device 300 includes: a first determining module 301, a second determining module 302, a compensation module 303, and a drive module 304, wherein: the first determining module 301 is used to determine the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle; the preset mapping relationship represents the correspondence between the steering wheel angle and the actual displacement of the rack mechanism; the second determining module 302 is used to determine the basic feedback torque for the steering wheel based on the equivalent arm and the rack force corresponding to the rack mechanism; the compensation module 303 is used to compensate the basic feedback torque based on the steering wheel torque applied by the user to obtain the target feedback torque; and the drive module 304 is used to drive the upward drive motor based on the target feedback torque.

[0168] In some embodiments, the first determining module 301 is further configured to determine the current steering gear ratio based on the vehicle's real-time speed and the current steering wheel angle; construct a preset mapping relationship based on the steering gear ratio, the current steering wheel angle, and the transmission efficiency; and perform a differential operation on the preset mapping relationship relative to the current steering wheel angle to obtain an equivalent force.

[0169] In some embodiments, the drive module 304 is further configured to determine the desired displacement for the rack mechanism based on the steering gear ratio and the current steering wheel angle; and to determine the downward drive torque of the downward drive motor based on the desired displacement, so as to drive the rack mechanism to move based on the downward drive motor.

[0170] In some embodiments, the second determining module 302 is further configured to determine the inertial force of the rack mechanism based on the mass of the vehicle and the displacement acceleration of the rack mechanism; determine the damping force of the rack mechanism based on the displacement velocity of the rack mechanism and the damping coefficient of the vehicle; and determine the rack force based on the damping force of the rack mechanism, the inertial force of the rack mechanism, and the downward driving torque.

[0171] In some embodiments, the compensation module 303 is further configured to determine a target compensation coefficient based on steering wheel torque and vehicle operating data; and to determine a target feedback torque based on the target compensation coefficient and the basic feedback torque.

[0172] In some embodiments, the operating data includes the vehicle yaw rate, the angular acceleration of the up-rotation drive motor, and the rotational speed of the up-rotation drive motor; the compensation module 303 is further configured to determine the external force compensation coefficient based on the steering wheel torque; determine the motion compensation coefficient based on the vehicle yaw rate; determine the motor compensation coefficient based on the angular acceleration and rotational speed of the up-rotation drive motor; and determine the target compensation coefficient based on the external force compensation coefficient, the motion compensation coefficient, and the motor compensation coefficient.

[0173] The descriptions of the apparatus embodiments above are similar to those of the method embodiments, and have similar beneficial effects. In some embodiments, the functions or modules included in the apparatus provided in this application can be used to perform the methods described in the method embodiments. For technical details not disclosed in the apparatus embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0174] This application provides a vehicle including a memory, a vehicle controller, and a steering system. The memory stores a computer program that can run on the vehicle controller. When the vehicle controller executes the program, it implements some or all of the steps in the above-described method. The steering system includes an upward steering mechanism and a downward steering mechanism. The upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel. The downward steering mechanism includes a rack mechanism and a downward steering drive motor.

[0175] This application provides a computer-readable storage medium storing a computer program. When the computer program is run by a vehicle controller, it implements the aforementioned method. The computer-readable storage medium can be transient or non-transient.

[0176] It should be noted that, in the embodiments of this application, if the above methods are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, or the part that contributes to the related technology, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions for executing all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), magnetic disks, or optical disks. Thus, the embodiments of this application are not limited to any specific hardware, software, or firmware, or any combination of hardware, software, and firmware.

[0177] This application provides a computer program including computer-readable code. When the computer-readable code is executed in the computer program, the vehicle controller performs some or all of the steps in the method described above.

[0178] This application provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program. When the computer program is read and executed by a computer, it implements some or all of the steps in the above-described method. This computer program product can be implemented specifically through hardware, software, or a combination thereof. In some embodiments, the computer program product is specifically embodied as a computer storage medium; in other embodiments, the computer program product is specifically embodied as a software product, such as a software development kit (SDK).

[0179] It should be noted that the descriptions of the various embodiments above tend to emphasize the differences between them, while their similarities or commonalities can be referenced interchangeably. The descriptions of the vehicle, storage medium, computer program, and computer program product embodiments above are similar to the descriptions of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the vehicle, storage medium, computer program, and computer program product embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0180] This application provides a vehicle, such as... Figure 4 As shown, the hardware entities of vehicle 400 include: vehicle controller 401, communication interface 402, memory 403, bus 404, and steering system 405, wherein: The vehicle controller 401 typically controls the overall operation of the vehicle 400.

[0181] Communication interface 402 enables vehicle 400 to communicate with other terminals or servers via a network.

[0182] The memory 403 is configured to store instructions and applications executable by the vehicle controller 401, and can also cache data to be processed or already processed (e.g., image data, audio data, voice communication data, and video communication data) of the vehicle controller 401 and various modules in the vehicle 400. It can be implemented using flash memory or random access memory (RAM). Data transfer between the vehicle controller 401, the communication interface 402, and the memory 403 can be performed via bus 404.

[0183] The vehicle controller 401 executes instructions and applications to implement the steps of any of the above methods. The vehicle controller 401 typically controls the overall operation of the vehicle 400.

[0184] The steering system 405 includes an upward steering mechanism and a downward steering mechanism; the upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel; the downward steering mechanism includes a rack mechanism and a downward steering drive motor.

[0185] It should be understood that the phrase "an embodiment" or "one embodiment" mentioned throughout the specification indicates that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above steps / processes do not indicate the order of execution; the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The above embodiment numbers are for descriptive purposes only and do not indicate the superiority or inferiority of the embodiments.

[0186] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0187] In the several embodiments provided in this application, it should be understood that the disclosed apparatus, vehicle, and method can be implemented in other ways. The apparatus and vehicle embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the vehicle or unit may be electrical, mechanical, or other forms.

[0188] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0189] In addition, each functional unit in the various embodiments of this application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0190] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0191] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence or the part that contributes to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a device to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0192] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A steering control method applied to a vehicle, wherein the vehicle's steering system includes an upward steering mechanism and a downward steering mechanism; the upward steering mechanism includes an upward steering drive motor rigidly connected to a steering wheel; The downward rotating mechanism includes a rack and pinion mechanism and a downward rotating drive motor; the method includes: Based on a preset mapping relationship and the current steering wheel angle, the equivalent force arm between the steering wheel and the rack mechanism is determined; the preset mapping relationship characterizes the correspondence between the steering wheel angle and the actual displacement of the rack mechanism. Based on the equivalent force arm and the rack force corresponding to the rack mechanism, the basic feedback torque for the steering wheel is determined. The target feedback torque is obtained by compensating the basic feedback torque based on the steering wheel torque applied by the user. The upward drive motor is driven based on the target feedback torque.

2. The method according to claim 1, characterized in that, The step of determining the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle includes: The current steering gear ratio is determined based on the vehicle's real-time speed and the current steering wheel angle. The preset mapping relationship is constructed based on the steering gear ratio, the current steering wheel angle, and the transmission efficiency. The equivalent arm is obtained by performing a differential operation on the preset mapping relationship relative to the current steering wheel angle.

3. The method according to claim 2, characterized in that, The method further includes: Based on the steering ratio and the current steering wheel angle, determine the desired displacement for the rack mechanism; The downward driving torque of the downward drive motor is determined based on the desired displacement, so as to drive the rack mechanism to move based on the downward drive motor.

4. The method according to claim 3, characterized in that, The method further includes: The inertial force of the rack mechanism is determined based on the mass of the vehicle and the displacement acceleration of the rack mechanism. The damping force of the rack mechanism is determined based on the displacement velocity of the rack mechanism and the damping coefficient of the vehicle. The rack force is determined based on the damping force of the rack mechanism, the inertial force of the rack mechanism, and the downward driving torque.

5. The method according to any one of claims 1 to 4, characterized in that, The process of compensating the base feedback torque based on the steering wheel torque applied by the user to obtain the target feedback torque includes: Based on the current steering wheel torque and the vehicle's operating data, determine the target compensation coefficient; The target feedback torque is determined based on the target compensation coefficient and the basic feedback torque.

6. The method according to claim 5, characterized in that, The operating data includes the vehicle yaw rate, the angular acceleration of the upward drive motor, and the rotational speed of the upward drive motor; The determination of the target compensation coefficient based on the current steering wheel torque and the vehicle's operating data includes: Determine the external force compensation coefficient based on the current steering wheel torque; Based on the vehicle's yaw rate, determine the motion compensation coefficient; Based on the angular acceleration and rotational speed of the upper drive motor, the motor compensation coefficient is determined; The target compensation coefficient is determined based on the external force compensation coefficient, motion compensation coefficient, and motor compensation coefficient.

7. The method according to claim 5, characterized in that, The method further includes: The inertial torque of the steering wheel is determined based on the steering wheel angular acceleration and the steering wheel moment of inertia. The damping torque of the steering wheel is determined based on the angular velocity and damping coefficient of the steering wheel. The steering wheel torque is determined based on the inertial torque of the steering wheel, the damping torque of the steering wheel, the upward driving torque of the upward drive motor, and the frictional torque of the steering wheel.

8. A steering control device, characterized in that, Applied to vehicles, the vehicle's steering system includes an upward steering mechanism and a downward steering mechanism; the upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel; The downward rotation mechanism includes a rack and pinion mechanism and a downward rotation drive motor; the device includes: The first determining module is used to determine the equivalent arm between the steering wheel and the rack mechanism based on a preset mapping relationship and the current steering wheel angle; the preset mapping relationship represents the correspondence between the steering wheel angle and the actual displacement of the rack mechanism; The second determining module is used to determine the basic feedback torque for the steering wheel based on the rack force corresponding to the equivalent force arm and the rack mechanism. The compensation module is used to compensate the basic feedback torque based on the steering wheel torque applied by the user to obtain the target feedback torque; A drive module is used to drive the upward drive motor based on the target feedback torque.

9. A vehicle comprising a memory, a vehicle controller, and a steering system, wherein the memory stores a computer program executable on the vehicle controller, characterized in that, When the vehicle controller executes the program, it implements the steps of the method according to any one of claims 1 to 7; the steering system includes an upward steering mechanism and a downward steering mechanism; the upward steering mechanism includes an upward steering drive motor rigidly connected to the steering wheel; the downward steering mechanism includes a rack mechanism and a downward steering drive motor.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 7.

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